The present invention relates to a key duplicating machine, and more particularly to an improved key duplicating machine having a rotating cutting tool directly secured on an output shaft of a driving motor, a duplicating stylus arranged on a rack means and can be adjusted by hand; a pair of clamping devices secured on a rectangular base releasably secured on an upper slide slidably secured on a lower slide slidably secured on a substrate; and a compression spring arranged between the upper slide and the rear wall of the lower slide for forcing a key blank to move towards and touch a rotating cutting tool for effecting the key cutting.
Conventional key duplicating machine has the following disadvantages:
The cutting tool is driven through an intermediate belt and pulley assembly by the output shaft of a driving motor. This will increase not only the number of the parts, but also the transmission friction loss.
The duplicating stylus can only be adjusted by a tool e.g. a driver or a spanner, and hence it is inconvenient to the user.
The clamping device is stationarily provided on the duplicating machine, and can only be used to clamp a specific type of the key.
The key cutting is effected by means of the hand strength control, i.e. the hand is used to manipulate the clamping device in order to urge a key blank clamped on the clamping device to move towards and touch a rotating cutting tool for effecting the key cutting. In such a key cutting, it is not easy for a new hand to control the strength because improper exertion of the strength on the clamping device will result in an inaccurate key cutting, i.e. inaccurate depths of the formed key teeth. Hence, such a duplicating machine is merely suitable for an old hand, and not for a new hand.
Briefly, the present invention aims at eliminating the above disadvantages and provides an improved key duplicating machine which is suitable both for a new hand and an old hand, and having a rotating cutting tool which is directly secured on the shaft of a motor without an intermediate belt and pulley assemble; a duplicating stylus which can be adjusted by hand; a pair of clamping devices for clamping a key blank and a key sample, which is releasably secured through a rectangular base by means of the bolts, and hence it can be removed from the duplicating machine, and other different type of the pair of the clamping devices can be used to replace the removed one; and a compression spring arranged for constantly forcing the key blank to move toward and touch the rotating cutting tool for effecting the key cutting, without hand strength control.
In one aspect of the present invention, the improved key duplicating machine comprises a rotating cutting tool directly secured on an output shaft of a driving motor; a duplicating stylus secured on a rack means secured on a substrate, and can be adjusted by hand; a pair of clamping devices for clamping a key blank and a key sample, secured on a rectangular base formed in a flat plate for partial engagement with a slot formed on an upper slide, and releasably secured on the said upper slide slidably secured on a lower slide slidably secured on the said substrate; a compression spring arranged between the said upper slide and the rear wall of the said lower slide for constantly forcing a key blank to move toward and touch the said rotating cutting tool for effecting the key cutting.
In another aspect of the present invention, the improved key duplicating machine comprises a rotating cutting tool directly secured on an output shaft of a driving motor; a duplicating stylus secured on a rack means secured on a substrate, and can be adjusted by hand; a pair of clamping devices for clamping a key blank and a key sample, secured on a rectangular base formed in a flat plate for partial engagement with a slot formed on an upper slide, and releasably secured on the said upper slide slidably secured on a lower slide slidably secured on the said substrate; a compression spring arranged between the said upper slide and the rear wall of the said lower slide for constantly forcing a key blank to move toward and touch the said rotating cutting tool for effecting the key cutting; and a lead screw and nut assembly comprising a lead screw connected at one end to a hand wheel horizontally rotatably secured on a support secured on a vertical support of the said rack means, and a nut threadedly engaged with the said lead screw, and releasably secured on a vertical wall of a L-shaped member secured on a right side of the said lower slide, for driving the said key blank to move leftward or rightward by rotation of the said hand wheel to effect a steady key cutting.
Preferably the key duplicating machine further comprises a spring retainer provided between the said upper slide and the said lower slide, and comprising a retaining rod formed in a lever, and slantingly downward pivotally secured on a right side of the said upper slide, and having a downward recess formed on a front portion thereof for engagement with a stud secured on the said right side of the said upper slide by means of a torsion spring provided on a pivot of the said retaining rod, and having one end hooked at a rear potion of the said retaining rod and the other end hooked at the said stud; and a retaining plate secured on the said right side of the said lower slide, and having an upward protrusion formed on the top thereof for locking a hook formed at the front end of the said retaining rod when the said upper slide together with the said retaining rod is moved rearward by turning the said handle in a clockwise direction until the said hook has been raised by the said protrusion and fallen into a space behind the said protrusion, in order to enable the said upper slide to move to a non-cutting position.